Hi....have travelled with ryan air but not with a child - however generally speaking most airlines are quite family friendly and will seat you all together without you having to request it. Howevere if you want to make certain - when you check in just mention it to the check in assistant and they should be absolutely fine about it...

when my baby was tiny we used to travel a lot (also with Ryanair - as we both work in the travel industry) I used to find it much easier to change my son's clothes whith wrap-over vests I've found on [Advert Removed] - they open flat and are easy to put on any baby sleeping or awake specially when space is limited. and you don't have to pull them over your baby's head which used to send my little one screaming every time. try them if you like and let me know what you think [Advert Removed]